Agent Skills › calesthio/OpenMontage › video-edit

video-edit

GitHub

提供基于 ffmpeg/ffprobe 的本地视频编辑能力，涵盖裁剪、拼接、缩放、变速、音频提取替换、压缩、格式转换及添加水印等核心功能，并附带主流社交平台分辨率预设。

.claude/skills/video-edit/SKILL.md calesthio/OpenMontage

Trigger Scenarios

需要裁剪或切割视频片段需要将多个视频片段拼接在一起需要调整视频尺寸以适配社交媒体平台需要提取或替换视频中的音频需要对视频进行压缩或格式转换

Install

npx skills add calesthio/OpenMontage --skill video-edit -g -y

More Options

Non-standard path

npx skills add https://github.com/calesthio/OpenMontage/tree/main/.claude/skills/video-edit -g -y

Use without installing

npx skills use calesthio/OpenMontage@video-edit

指定 Agent (Claude Code)

npx skills add calesthio/OpenMontage --skill video-edit -a claude-code -g -y

安装 repo 全部 skill

npx skills add calesthio/OpenMontage --all -g -y

预览 repo 内 skill

npx skills add calesthio/OpenMontage --list

SKILL.md

Frontmatter

{
    "name": "video-edit",
    "description": "Edit videos locally using ffmpeg. Trim, concat, resize, speed, overlay, extract audio, compress, and convert.\nUse when: (1) Trimming or cutting video segments, (2) Concatenating multiple clips, (3) Resizing video for social platforms,\n(4) Extracting or replacing audio, (5) Compressing video, (6) Converting video formats, (7) Getting video info."
}

Video Edit

Edit videos locally by running ffmpeg/ffprobe directly. No wrapper scripts needed.

Prerequisites

Install ffmpeg (includes ffprobe):

# macOS
brew install ffmpeg

# Ubuntu/Debian
sudo apt update && sudo apt install -y ffmpeg

# Verify
ffmpeg -version && ffprobe -version

Quick Reference

Get video info

ffprobe -v quiet -print_format json -show_format -show_streams video.mp4

Trim

ffmpeg -y -ss 00:00:30 -to 00:01:45 -i video.mp4 -c copy trimmed.mp4

Concatenate clips

# 1. Create a file list
printf "file '%s'\n" clip1.mp4 clip2.mp4 clip3.mp4 > list.txt

# 2. Concat with stream copy
ffmpeg -y -f concat -safe 0 -i list.txt -c copy joined.mp4

Resize for platform

ffmpeg -y -i video.mp4 \
  -vf "scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2:black" \
  -c:a copy tiktok.mp4

Change speed

# 2x faster
ffmpeg -y -i video.mp4 -filter:v "setpts=0.5*PTS" -filter:a "atempo=2.0" fast.mp4

# 0.5x (slow motion)
ffmpeg -y -i video.mp4 -filter:v "setpts=2.0*PTS" -filter:a "atempo=0.5" slow.mp4

Extract audio

ffmpeg -y -i video.mp4 -vn -acodec libmp3lame audio.mp3

Replace audio

ffmpeg -y -i video.mp4 -i audio.mp3 -c:v copy -map 0:v:0 -map 1:a:0 -shortest output.mp4

Compress

ffmpeg -y -i video.mp4 -crf 23 -preset medium -c:a copy compressed.mp4

Convert format

ffmpeg -y -i video.mov output.mp4

Add image overlay

# Logo in top-right corner
ffmpeg -y -i video.mp4 -i logo.png \
  -filter_complex "overlay=W-w-10:10" -c:a copy watermarked.mp4

Platform Presets

Platform	Resolution	Scale + pad filter
TikTok	1080 x 1920	`scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2:black`
YouTube	1920 x 1080	`scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2:black`
Instagram	1080 x 1350	`scale=1080:1350:force_original_aspect_ratio=decrease,pad=1080:1350:(ow-iw)/2:(oh-ih)/2:black`
Square	1080 x 1080	`scale=1080:1080:force_original_aspect_ratio=decrease,pad=1080:1080:(ow-iw)/2:(oh-ih)/2:black`
Twitter/X	1920 x 1080	`scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2:black`

Use the filter with: ffmpeg -y -i input.mp4 -vf "<filter>" -c:a copy output.mp4

Tips

Always use -y to overwrite output without prompting.
Use -c copy when you only need to cut/join (no re-encoding, very fast).
Lower CRF = better quality, larger file. Range 18-28 is typical; 23 is the default.
For detailed recipes and flag explanations, see references/operations.md.